Hydrophilic / Hydrophobic

Hydrophilic describes substances that have an affinity for water (water-loving). Hydrophobic describes substances that repel water (water-fearing). Standard silicones are hydrophobic. Silicone surfactants modified with PEG or PPG groups become amphiphilic — having both hydrophilic and hydrophobic regions, which is what makes them effective emulsifiers.